docs: def split_prefix(self, ctx, item):
          """See if ``item`` has blueprint prefix, return (directory, rel_path).
          """
          app = ctx._app
          try:
              if hasattr(app, 'blueprints'):
                  blueprint, name = item.split('/', 1)
                  directory = get_static_folder(app.blueprints[blueprint])
                  endpoint = '%s.static' % blueprint
                  item = name
              else:
                  # Module support for Flask < 0.7
                  module, name = item.split('/', 1)
                  directory = get_static_folder(app.modules[module])
                  endpoint = '%s.static' % module
                  item = name
          except (ValueError, KeyError):
              directory = get_static_folder(app)
              endpoint = 'static'
  
          return directory, item, endpoint